Hearing assistance devices, such as hearing aids, can provide adjustable operational modes or characteristics that improve the performance of the hearing assistance device for a specific person or in a specific environment. Some of the operational characteristics include, but are not limited to volume control, tone control, directionality, and selective signal input. These and other operational characteristics can be programmed into a hearing aid. Advanced hearing assistance devices, such as digital hearing aids, may be programmed to change from one operational mode or characteristic to another depending on algorithms operating on the device. As the person wearing a hearing assistance device moves between different acoustic environments, it may be advantageous to change the operational modes or characteristics of the hearing assistance device to adjust the device to particular acoustic environments. Some devices may possess signal processing adapted to classify the acoustic environments in which the hearing assistance device operates. However, such signal processing may require a relatively large amount of signal processing power, be prone to error, and may not yield sufficient improvement in cases when processing power is available. Certain environments may be more difficult to classify than others and can result in misclassification of the environment or frequent switching of the detected environment, thereby resulting in reduced hearing benefits of the hearing assistance device. One problematic environment is that of a vehicle, such as an automobile. Wearers of digital hearing aids in moving vehicles are exposed to a variety of sounds coming from the vehicle, open windows, fans, and sounds from outside of the vehicle. Users may experience frequent mode switching from adaptive devices as they attempt to adjust rapidly to changing acoustic environmental inputs.
There is a need in the art for an improved system for determining acoustic environments in hearing assistance devices.